1. Field of the Invention
This invention is related to writing instruments, and more particularly to a rechargeable writing instrument, having a unique retractor mechanism which provides for greater convenience and ease in use and greater efficiency in manufacturing than known retractor mechanisms.
2. Discussion of Related Art
Writing instruments having a retracting cartridge element disposed in an elongated barrel are well known in the art. Examples of such writing instruments include: U.S. Pat. Nos. 4,995,750; 4,551,035; and 3,637,316. These instruments generally comprise a retractor mechanism having integral biasing means for maintaining the retractor mechanism in a fixed position corresponding to the cartridge being protracted from the barrel. Such retractor mechanisms can have resilient spring portions which may be forcibly deformed for moving the cartridge from the protracted position to a retracted position within the barrel of the writing instrument. However, over time, and after repeated operations, the resilient spring portions of such mechanisms can fatigue and eventually fail. In addition, these retractor mechanisms are designed in such a manner so that recharging can become a difficult task, requiring great dexterity and a considerable amount of time.
It is desirable therefore, to provide a retractable writing instrument having a removable plunger mechanism which can be easily disassembled from the barrel of the instrument so that a spent writing cartridge can be quickly replaced.